GE M60 UR Series, Instruction Manual

Page: 349 / 662

GE Multilin M60 Motor Protection System 5-221
5 SETTINGS 5.7 CONTROL ELEMENTS
5
“Acknowledge” mode of operation. The acknowledging signal must appear within the time defined by the
SELECTOR
TIME-OUT
setting after the last activity of the three-bit control inputs. Note that the stepping up control input and three-
bit control input have independent acknowledging signals (
SELECTOR 1 ACK
and
SELECTOR 1 3BIT ACK
, accordingly).
• SELECTOR 1 POWER-UP MODE : This setting specifies the element behavior on power up of the relay.
When set to “Restore”, the last position of the selector (stored in the non-volatile memory) is restored after powering up
the relay. If the position restored from memory is out of range, position 0 (no output operand selected) is applied and
an alarm is set (
SELECTOR 1 PWR ALARM
).
When set to “Synchronize” selector switch acts as follows. For two power cycles, the selector applies position 0 to the
switch and activates
SELECTOR 1 PWR ALARM
. After two power cycles expire, the selector synchronizes to the position
dictated by the three-bit control input. This operation does not wait for time-out or the acknowledging input. When the
synchronization attempt is unsuccessful (that is, the three-bit input is not available (0,0,0) or out of range) then the
selector switch output is set to position 0 (no output operand selected) and an alarm is established (
SELECTOR 1 PWR
ALARM
).
The operation of “Synch/Restore” mode is similar to the “Synchronize” mode. The only difference is that after an
unsuccessful synchronization attempt, the switch will attempt to restore the position stored in the relay memory. The
“Synch/Restore” mode is useful for applications where the selector switch is employed to change the setting group in
redundant (two relay) protection schemes.
• SELECTOR 1 EVENTS : If enabled, the following events are logged:
EVENT NAME DESCRIPTION
SELECTOR 1 POS Z Selector 1 changed its position to Z .
SELECTOR 1 STP ALARM The selector position pre-selected via the stepping up control input has not been
confirmed before the time out.
SELECTOR 1 BIT ALARM The selector position pre-selected via the three-bit control input has not been confirmed
before the time out.